Like Dexal said, the rule would just be that you can only delay your turn after starting your turn so that particular exploit wouldn't work
I think you and Dex both missed the part where the stun doesn't end until the *End* of your next turn. If you delay your turn, then you are not ending your turn and your turn hasn't ended. If it has ended, then what you're doing later isn't a delayed turn, it's a second turn, or it's a held reaction... in which case we're back to the ready action needing to be properly implemented.
